Posts Tagged deficiency
Feb 21, 2019 | Original Press Release from the University of Queensland
Associate Professor Thomas Burne at UQ’s Queensland Brain Institute led the studies, which provide the groundwork for research into better prevention and treatments.
“Over a billion people worldwide are affected by vitamin D deficiency, and there is a well-established link between vitamin D deficiency and impaired cognition,” Dr Burne said.
“Unfortunately, exactly how vitamin D influences brain structure and function is not well understood, so it has remained unclear why deficiency causes problems.”
Dr Burne’s team found that vitamin D levels affect a type of ‘scaffolding’ in the brain, called perineuronal nets.
“These nets form a strong, supportive mesh around certain neurons, and in doing so they stabilise the contacts these cells make with other neurons,” he said.
Researchers removed vitamin D from the diet of a group of healthy adult mice, and after 20 weeks found a significant decline in their ability to remember and learn compared to a control group.
Dr Burne said the vitamin D deficient group had a pronounced reduction in perineuronal nets in the hippocampus, the brain region crucial to memory formation.
“There was also a stark reduction in both the number and strength of connections between neurons in that region.”
UQ researchers propose that when vitamin D levels drop, certain enzymes become unchecked and begin to break down perineuronal nets. (Nick Valmas, UQ)Dr Burne’s team propose that vitamin D plays an important role in keeping perineuronal nets stable, and that when vitamin D levels drop, this ‘scaffolding’ is more easily degraded by enzymes.
“As neurons in the hippocampus lose their supportive perineuronal nets, they have trouble maintaining connections, and this ultimately leads to a loss of cognitive function.”
Associate Professor Burne said the hippocampus may be most strongly affected by vitamin D deficiency because it is much more active than other brain regions.
“It’s like the canary in the coalmine—it might fail first because its high energy requirement makes it more sensitive to the depletion of essential nutrients like vitamin D.
“Intriguingly, the right side of the hippocampus was more affected by vitamin D deficiency than the left side.”
Associate Professor Burne said loss of function in this area could be an important contributor to the hallmarks of schizophrenia, including severe memory deficits and a distorted perception of reality.
“The next step is to test this new hypothesis on the link between vitamin D deficiency, perineuronal nets and cognition,” he said.
“We are also particularly excited to have discovered these nets can change in adult mice.
“I’m hoping that because they’re dynamic there is a chance that we can rebuild them, and that could set the stage for new treatments.”
This article has been republished from materials provided by the University of Queensland. Note: material may have been edited for length and content. For further information, please contact the cited source.
Reference: Mayne, P. E., & Burne, T. H. J. (2019). Vitamin D in Synaptic Plasticity, Cognitive Function, and Neuropsychiatric Illness. Trends in Neurosciences, 0(0). https://doi.org/10.1016/j.tins.2019.01.003
Growing up, I always remembered vitamin D as being the ’sunshine vitamin’. However, since starting my nursing training, I have been interested in researching the importance and health benefits of vitamin D.
In the UK, we are encouraged to eat a healthy, balanced diet. This provides all needed nutrients excluding vitamin D. Oily fish has been identified as a significant source, whereas meat, egg yolks and other fortified foods, including margarine and some breakfast cereals, provide smaller amounts.
The prevalence of vitamin D deficiency in the UK is significant: during the winter, 30-40% of people in the general population and belonging to all age groups are vitamin D deficient. Near the end of the summer months, 13% of adolescents and 8% of adults are vitamin D deficient.
The intake of vitamin D and its status are imperative for overall health and wellbeing, as well as for bone and calcium-phosphate metabolism.
Without adequate vitamin D, bones may become brittle, thin or misshapen. Literature suggests that sufficient vitamin D status is protective against autoimmune diseases, cardiovascular disease, musculoskeletal disorders, neurocognitive dysfunction and respiratory infections.
Compared to the general population, individuals with learning disabilities have an increased risk of developing low bone mineral density, osteopenia, osteoporosis and fractures. This is mainly attributed to the higher prevalence of obesity or undernutrition, inactive lifestyles and polypharmacy.
Epilepsy is the most common neurological condition within the learning disability population. One in four people with a learning disability experience epilepsy, compared to one in five in the general population.
”The identified prevalence of vitamin D deficiencies among epilepsy patients is high”
Approximately, 30% of individuals with learning disabilities are prescribed anti-epileptic drugs (AEDs), an identified risk factor for fractures and low bone-mass density. Reasons for this have not been definitively known, but it could potentially be due to AEDs breaking down the body’s vitamin D stores at a higher degree than normal.
Consequently, this could result in AEDs causing a vitamin D deficiency, which could potentially lead to osteoporosis and osteomalaica and an increased risk of fractures.
The identified prevalence of vitamin D deficiencies among epilepsy patients is high, however, the number of research studies assessing the effect of vitamin D on seizure control is limited.
One of these research studies, conducted in 2012, measured vitamin D levels and through the administration of vitamin D3, normalised levels in 13 patients with pharmacoresistant epilepsy.
To identify whether vitamin D3 was impactful on seizure frequency, the study compared numbers of seizures during a 90-day period, prior and following treatment commencement. The study found the median seizure reduction to be 40% and concluded that normalisation of vitamin D levels can have an anticonvulsant effect.
Due to very little evidence on the effect of vitamin D on epilepsy, it is acknowledged that this area needs researched further. However, as nurses this is something we could be mindful of.